The most strategically important half mile in the Caribbean in the 16th and 17th centuries - the entrance to San Juan harbour. Puerto Rico was important because it was the first large island encountered by ships coming from Europe. None of the Lesser Antilles had enough water for a large army. So, if you wanted to go running around with your army and navy, grabbing up real estate, you needed a base like this. The fort was attacked numerous times over the centuries, by the Dutch and the English. It took over 250 years to build all of the fortifications. The only things missing are the cannon. Over the years they have been thrown in the sea, melted down or otherwise lost. It would really look impressive if there were original cannon in all the embrasures like in Old Quebec.